Marine steering gear motor



T. MCLEOD Feb. 15, 1938.

MARINE STEERING GEAR MOTOR Filed April 10, 1936 2 Sheets-Sheejl Y1 llllllll INVENTO ze BY U ATTORNEY Feb. l5, 1938. T. Mou-:0D

MARINE STEERING GEAR MOTOR Filed April 1o, 1956 2 sheets-sheet 2 RSN @n N" NNN N INVENTo A5@ ATTORNEY Patented Feb. 15, 1938 UNITED STATES PATENT OFFICE MARINE STEERING GEAR Mo'roR Thomas McLeod, Elizabeth, N. J. Application April io, 1936, serial No. 73,638

3 Claims.

'This invention relates to marine steering apparatus, and more'particularly to improvements in steering apparatus of thehydraulic type.

Heretofore, in marine steering gear, it has been the practice to operate a rudder arm by 'a pair of opposed hydraulic rams in which the operating fluid, usually oil, is circulated by a pump, and the admission and emission of the liquid to the cylinders of the rams is controlled by a by-pass de. vice connected with liquid transmission pipes. There have been numerous improvements and modifications of this type of steering apparatus; but all of such improvements have included the use of two opposed rams.

It is an object of this invention to provide a marine steering apparatusin which the use of two opposed hydraulic rams ls eliminated, thereby greatly decreasing the cost and weight of the apparatus, at the same time providing aA simple and highly eicient steering device for ships and the like.

A furtherv object is the provision of a steering apparatus of the hydraulic type in which a single cylinder is employed, the cylinder being movable over a stationary piston positioned therein, and an operating'uid is forced by means of a double-acting pump into the cylinder on both sides of the piston, the admission and emission of the fluid being controlledV by by-pass valves which determine the side of the piston to receive the greatest force of fluid in order to move the cylinder in a desired direction, the cylinder being connected to the rudder arm of a ship or the like.

A further object is the provision of a'n' operating mechanism employing a stationary piston positioned in a movable cylinder, and using a fluid as an operating means.

These and other advantageous objects, which will later appear are accomplished by the simple vand practical construction and arrangement of parts hereinafter described and exhibited in the accompanying drawings, forming part hereof,

and in which:

Fig. 1 is a plan view of a hydraulic steering apparatus 'embodying my invention,

Fig. 2'is a side elevational .View of the apparatus,

Fig. 3 is a side elevational view of the movable cylinder, in section, and

Fig. 4 is a plan view of the movable cylinder,

partially in section..

Referring to the drawings, the apparatus is shown to comprise a base I upon which are mounted brackets 2, supporting a pair of horizontal rods 3, slidably receiving arms 4 attached to a movable cylinder 5, in which is positioned a piston 6, provided on each side thereof with passages 1', communicating with fluid supply pipes 8 and 9,'said pipes respectively passing throughv the operating fluid, which is usuallyv oil, suitable packing is provided about pipes I4, 8 and 9.

The head I is provided with a passage I5 communicating with the section of the cylinder surf rounding pipe 8, and a -pipe I6 connects the section of the cylinder surrounding pipe 9 with the head Ill. e

Mounted in the `head I0 are a pair of opposed valves I1 and I8, associated respectively with pas- 'sage I5 and `pipe I6. -'I'he valves I1 and I8 are spring controlled'and normally tend to seat to prevent theow of oil from passage I and passage I9, (which passage communicates with pipe I6) into a common chamber 20 opening into. a-

passage 2I communicating with pipe I4. Small bleeder valves 22 are providedto take care of excess pressure due to rudder shocks or any other overload, the bleeder valves 22 opening into passages 23 communicating with passage 2l.

Rotatably. mounted in head I0 and passing through chamber 20 is a stub shaft 24 having integral therewith an arm 25 which engages the v web-like stems 26 of valves I1 and I8 to hold them open when the arm is in the position shown in Fig. 4.

The shaft 24 has xed to the lower end thereof a lever 21 pivoted at 28 to a bar 29 slidably mounted in arms 30 projecting from heads I0 Vand II, (see Fig. 1). The lever 21 is also attached to a bar 3I supporting a pair of pulleys 32 and 33, over which pass cables 34 and 35, each of which have one end thereof attached to arms 36 projecting from the heads I0 and II, and the `other end connected with a hand Wheel or other manually or automatically controlled device for steering (not shown),

Head II has connected thereto a pair of arms 31 pivotally connected to a forked rudder arm 38. One of the arms 4 is provided with stops 39 and 49 adapted to engage lever 21 to limit swinging movement thereof.

Also projecting from heads II) and Il are arms 4I, similar to arms 39, and slidably supporting'a bar 42, the latter having a pair of stops 43 8 and 9 into the passages 1 in piston 5 and thence into sections of the cylinder 5 on both sides of the piston 6. When the arm 25v is in the position shown in Fig. 4, whereby valves I1 and I8 are both held open, the oil flows through passage I5 and pipe l5, through valves I1 and IS and pipe I3, back to the pump I2. This substantially is a neutral position. When it is desired to turn the rudder to steer in a desired direction, the hand wheel is rotated, to tighten up on one of the cables 34 or 35. For example, when cable 34 is tightened, there is a pull on lever 21 to rotate shaft 24 to cause the arm 25 to hold valve I8v open and allow valve I1 to close. Now, the oil flows freely through the section of the cylinder 5 associated with pipe I5, but flow of oil is stopped through passage I5, thus building up pressure in the section. of the cylinder receiving oil from pipe 8. Since the piston 6 is stationary, this building up of pressure causes the cylinder 5 to move to the left, moving the rudder arm 38 with it. When the rotation of the hand wheel has ceased, bar 3I becomes a fulcrum for lever 21, pivoting on bar 3|. The lever 21 swings to the neutral position by the movement of the cylinder and `automatically opens valve I1 to stop cylinder 5. The cylinder 5 and arm 38 will remain in the positions to which they have been moved until the lever 21 is moved again to close valve I8 and open valve I1 to cause pressure to build up in the section of the cylinder surrounding pipe 9 to cause the cylinder 5 to move in the opposite direction.

In the event of Va failure of pump or other parts of the apparatus to operate' properly, and it is desired to manuallyA operate the rudder arm 38, I the cables 41 or 48 are tightened to slide the bars.

29 and 42 in one direction or the other. Assume that cable 41 is tightened, there will first vbe a pull on bar 29, because it is restrained by the lever 21. A pull on bar 29 will rotate lever 21 to open-valve I1, after which the arm 44 will engage one of the stops 43 thus causing bars 29 and 42 to move together, and to move cylinder 5 and its associated parts to the right to move rudder 38 in the same direction. During the movement of the cylinder 5 the liquid in the cylinder is ejected through passage I5 and valve I1 into pipes I4 and I3 back to supply tank I2.

From the above description it will be seen that there has been provided a simple and effective hydraulic steering apparatus which eliminates the necessity cf heavy opposed hydraulic rams. While the device has been described with reference to marine steering apparatus, it is obvious that it can be effectively'ernployed in many other situations.

- The foregoingl disclosure is to be regarded as -claim as new and desire to secure by Letters Patent, is:

1. In a marine steering apparatus of the hydraulic type, a stationary piston, a movable cylinder slidable over said piston, apump, means for conveying oil from said pump to said cylinder on both sides of the piston, said piston having heads closing each end thereof, one of said heads having a chamber, means for conveying oil from said cylinder to said chamber, valves mounted in said head controlling the ow of oil into the chamber, means tending constantly to close said valves, means communicating with the chamber for conveying oil back to the pump, a stub shaft mounted in the chamber, an arm on said shaft adapted to engage and increase the opening of one of the valves and to allow the other valve to close, a lever xed to said shaft, a bar fixed to one end of the lever, a pair of pulleys mounted on said bar, cables passing over the pulleys, each of said cables having one end thereof fixed to a part movable with the cylinder so that a pull upon one of the cables and a slackening upon the other will effect a movement of the lever to rotate the stub shaft to cause the arm to further open one of the valves and to allow the other valve to close, and arms mounted on the other head of the cylinder and pivotally connected to a rudder arm.

2. In a marine steering apparatus of the hydraulic type, a stationary piston, a movable cylinder slidable over said piston, a pump, means for conveying oil from said pump to said cylinder on both sides of the piston, said piston having other valve to close, a lever fixed to said shaft, a.

bar fixed to one end of the lever, a pair of pulleys mounted on said bar, cables passing over the pulleys, each of said cables having one end thereof fixed to a part movable with the cylinder so that a pull upon one of the cables and a slacken- 'ing upon the other will effect a movement of the lever to rotate the stub shaft to cause the arm to further open one of the valves and to allow the other valve to close, arms mounted on the other head of the cylinder and pivotally connected to a rudder arm, a pair of spaced bars slidably supported by the cylinder, cables connecting the ends ofsaid bars, one of said bars being pivotally connected to said lever, spaced .stops on the other bar, and an arm fixed to said stub shaft and adapted to engage one of said stops when the spaced bars are moved in the same direction.

3. In a marine steering apparatus of the hydraulic type, a movable cylinder, arms connecting said cylinder to a rudder arm, a stationary piston positioned in said cylinder and over which said cylinder slides, a pump for supplying an operating fluid to the cylinder on both sides of said piston, valve means for controlling the circulation and return of said operating fluid to the pump, a head for the cylinder, a stub shaft mounted in said head, an arm on said shaft adapted to engage and control the extent of opening of said valve, a lever fixed to said shaft, a bar fixed to one end of the lever, a pair of pulleys mounted on said bar, cables passing over the pulleys, each of said cables having one end thereof fixed to a part movable with the cylinder, so that a pull upon one of the cables and a s'lackening' upon the other will effect a movement of the lever to rotatethe stub shaft to cause the ann to change the extent of opening of said valves, and arms mounted on the other end'of the cylinder pivotally connected to the rudder arm.

THOMAS McLEOD. 

